The operational principle of the measurement instrument is introduced , the circuit and characteristic of the integrated single channel pulse height analyzer and those of high performance adc are analyzed , and the measured real - time curves of liquid level and foam height are discussed 介绍了该测量仪的工作原理,分析了高速集成单道幅度分析器和高性能a / d转换器的电路及特点,讨论了液位曲线和泡沫高度曲线。